How can I add rows to a datagridview while the datagridview is bounded to an empty datatable

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C#

I have created a data table dbVisitor with empty rows and with two columns
then I create datagridview and put datagridview.datasource=dtVisitor;

then I write this code

dataGridView1.Rows.Add();
dataGridView1.Rows[0].Cells[0].Value = "1";
dataGridView1.Rows[0].Cells[1].Value = "2";
I got this error

"System.InvalidOperationException: 'Rows cannot be programmatically added to the DataGridView's rows collection when the control is data-bound."

so how can I addrows to a datagridview while this grid is bounded to an empty datatable

What I have tried:

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